A motor is to be mounted on a vehicle as a drive source. The motor includes a motor shaft extending in an axial direction, a drive gear provided on the motor shaft, a gear shaft extending in the axial direction, a driven gear provided on the gear shaft and coupled to the drive gear, a rotating member, an inner bearing that supports the gear shaft, and an outer bearing that supports the gear shaft. The rotating member is provided on the gear shaft and is configured to be coupled to a power transmission member that transmits power to a wheel of the vehicle. The rotating member is located between the inner bearing and the outer bearing in the axial direction.

A device configured to attach to a motor vehicle transmission housing enclosing the motor vehicle transmission is disclosed. The device includes a cover having an upper surface and a lower surface. The lower surface includes at least a first chamber and a second chamber, such that, once said cover is installed onto the motor vehicle transmission housing, the first chamber is in fluid communication with a motor vehicle crankcase and a motor vehicle oil tank, and the second chamber is in fluid communication with the motor vehicle transmission. The device includes a vent extending through the upper surface and the lower surface so as to vent pressure within said first chamber to the outside of said first chamber.

A transmission structure of electric clutchless motorcycle includes an electric motor, a variable speed gear set, a variable speed gear box and a gear position sensing unit. The arrangement of the gear position sensing unit is so configured that the transmission structure of electric clutchless motorcycle mechanism not only maintains the inertial energy recharge of the electric motor to increase the endurance of the vehicle, but also allows the driver to accurately control the speed control knob when switching gears, and furthermore can increase the automatic gear shift function of the electric gear shift design.

A vehicle has an engine; a drive pulley connected to and driven by a crankshaft of the engine; a driven pulley; an output shaft connected to and driven by the driven pulley; a belt looped around the pulleys; and a cover connected to the engine. The cover and the engine define a volume therebetween. A baffle disposed in the volume separates the volume in first and second chambers. The first chamber is disposed between the baffle and the engine. The second chamber is disposed between the baffle and the cover. The pulleys are disposed in the second chamber. The baffle defines first and second apertures fluidly communicating the first chamber with the second chamber. An air inlet is fluidly connected to the first chamber. An air outlet is fluidly connected to the second chamber.

Provided is a vehicle speed-change system including the following: a transmission positioned to the rear of a crank shaft of an engine; a transmission case that retains the transmission; a shift mechanism that has a shift cam which performs a speed-change operation of the transmission; and a shift actuator that operates the shift cam. The transmission includes a counter shaft positioned to the rear of the crank shaft, and a drive shaft to which rotation of the counter shaft is transmitted. The shift cam is positioned further to the rear than the counter shaft, and the shift actuator is arranged in a rear portion of the transmission case and to the rear of the shift cam.

A transmission structure of electric clutchless motorcycle includes an electric motor, a variable speed gear set, a variable speed gear box and a gear position sensing unit. The arrangement of the gear position sensing unit is so configured that the transmission structure of electric clutchless motorcycle mechanism not only maintains the inertial energy recharge of the electric motor to increase the endurance of the vehicle, but also allows the driver to accurately control the speed control knob when switching gears, and furthermore can increase the automatic gear shift function of the electric gear shift design.

A transmission of an internal combustion engine in which the shaft length of a main shaft can be shortened to eliminate a supporting wall around a reduction gear while a thrust load is received. Around a main shaft of a transmission of an internal combustion engine, a primary bearing is fastened to an inside of a primary driven gear, and is disposed between the primary driven gear and the main shaft. A collar member is disposed between the primary bearing and a main bearing. A step portion, in contact with the main bearing, is formed on the main shaft on an opposite side of the main bearing from the collar member. A cylindrical portion, an inner race of the primary bearing, the collar member, and an inner race of the main bearing are fastened to the side of the step portion.

There is provided a lubricating structure for a power transmission mechanism in which a crankshaft is coupled to a piston disposed in a cylinder bore and in which power is transmitted from the crankshaft to a camshaft. The lubricating structure includes: an idler gear that is configured to transmit power from the crankshaft to the camshaft; and an idler gear shaft that supports the idler gear via a bearing. One end portion of the idler gear shaft protrudes into the cylinder bore, and an oil passage configured to guide oil from the cylinder bore to the bearing is formed in the idler gear shaft.

An electric motorcycle includes a transmission gear set mounted in a gearbox housing and having a power input shaft inserted through a middle block of the gearbox and a power input pulley mounted on the power input shaft, an electric motor mounted on one side of the middle block and having a motor pulley mounted on the motor shaft thereof, and a transmission belt coupled between the motor pulley and the power input pulley for enabling the electric motor to rotate the power input shaft of the transmission gear set through the transmission belt, a gear shift pedal and a gear shift axle for gear shifting, and a speed output chain gear mounted on an output shaft of the transmission gear set and driven by the output shaft to rotate the rear wheel of the electric motorcycle through a chain.

A straddled vehicle, including a frame structure, a rear arm, a driving wheel rotatably supported by the rear arm, a power source unit, and a drive unit including a gear box, a drive motor and a control unit. The drive motor is arranged with an off-set toward a first direction from a center of the straddled vehicle, without overlapping the power source unit in a side view. The control unit is further in a second direction than the drive motor, and overlaps the drive motor, but does not overlap the power source unit, in the side view. The gear box is further in the second direction than the drive motor, and overlaps the drive motor in the side view. The gear box is also further in the first direction than the control unit, and overlaps with the control unit, but does not overlap the power source unit, in the side view.